Manufacture of aluminum chloride



Sept. 21 1926.

R. J.- DEARBORN MANUFACTURE OF ALUMINUM CHLORIDE Uriginal Filed Nov. 29,. 192

awwewtoz ori inal application filed November 29, 192;, Serial No. 518,540. Divided and this application filed.

February 26, 1925.

Patented Sept. 21,1926.

UNITEDZISVTATES P TENT, OFFICE.

RICHARD J. DEARBORN, OI SUMMIT, NEW JERSEY, ASSIGNOR TO THE TEXAS COM- I PANY, or nnw'yomgn. Y.,

A COR-PORATION OF TEXAS.

MANUFACTURE or ALnMrivUM cnLonrnn.

This invention relates to the production of metal chlorides and has particular reference to the reparation of anhydrousalumlnum chlori e in' relativelydarge quantities and'of a high degree of purity, and is a division of my copending application, Ser ial' Number 518,540, filed November 29, 1921,

: for improvements in 'manuf acture of aluminumchloride. i v v v k The aluminum ores wh ch are frequently used in the preparation of aluminum chloride commonly contain a greater or less I amount of impurities, chief among which are iron compounds. If such ores be treated with chlorin under conditions to form aluminum chloride, the resultant product 'will contain chlorides of iron or of other-metals which may be present in the aluminum ores.

In-ac'cordance with my invention the aluminum ore is treated to remove therefrom the iron and other impurities and the purified alumina is then chlorinated to produce.

an aluminum chloride uncontaminated with iron compounds.

The invention relates particularly to the production of .the chloride in a continuous manner. In the large scale production of aluminum chloride, it is advantageous to maintain the reaction chamber in continu- 7 step.

ous operation for some time and in accordance with my invention the aluminum ore is simultaneously preheated and treated to remove im critics and the aluminumfore thus heate and purified is continuously charged into a chlorination retort wherein the ore is treated to produce aluminum chloride, the ash formed in the reaction being continuously removed from the retort and the chloride vapors condensed and collected.

One phase of the invention consists in carrying on the preheating and purifying of the ore by means of waste heat from the alumina chlorinating retort, thereby conducting the preliminary treatment of the ore with a minimum of expense. Another feature of the invention is the coking of the aluminum. ore with carbonaceous material in the presence of a 'chlorinating agentso that impurities such 'as iron chloride may be removed from the ore during the coking I will now proceed to describe the invention in detail, reference being bad to the single figure of the accompanying drawing 'Serla1 No 11,646.

tion.

In the apparatus thus illustrated a fur-.

nace '10 having a combustion chamberll, is arranged to supply heat, preferably through checkered brickwork, to a retort 12 which .is constructedcf suitable refractory mate rial. The aluminum choride vapors are removed by a vapor line 13 to suitable condensers or collecting vessels. Ghlorin gas or other chlorinating agent is supplied to the' retort by means of a. pipe 14 which preferably enters near the bottom of the retort. As illustrated, the pipe communicates with an extension 15 formed at the bottom of the retort and Which depends into a rotatable pan 16. A plough 18 is'arranged to remove material in the pan to a predetermined depth so that'a certain amount of material may remain inthe pan to form a seal preventing either the, ingress or egress of gases to or from the retort while at the same time retort 12 in such manner that material may readily be transferred from the upper to the lower retort. In the arrangement illustrated the products discharged from'the retort 21 enters the hopper -22 havin a continuously operated gate 23 c0ntrol ed by a shaft 24which maybe operated by. any suitable mechanism. It is to be understood that any convenient arrangement for transferring materials from one retort to another may be used, but it is desirable to so design the apparatus as to reduce to a minimum the passage of gas from the alumina chlorinating retort into the purifying retortor vice versa. The retort21 is equipped with a pipe 25 for introducing the chlorinating agent and a conduit 26 for removing the iron chloride va ors or other vaporous products resulting rrom the preliminary treatment of the aluminum ore.

An oven .2? supplied "with heat by means of a burner or heat conduit 28 or. by any other' suitable means, 'is provided to preheatand coke the mixture of aluminum ore and reducing agent which it is desired to ch rinate. A conveyor 29 is adapted to continuously convey. material to be coked through the oven 27 The resultant coke is removed from the conveyor by any suitable mechanism, such as a rotatable scraper 30, and then discharged through a hopper 31 into, the retort 21. If desired, the coked product may be passed between rollers 32 for the purpose of crushing the coke into the size desired.

In using the apparatus illustrated an aluminum ore, such as bauxite, .aluminum Ltinuously charged into the retort 12 wheres or other chlorinating agent under a much" silicate, or other alumina containing clay. is mixed with carbonaceous material and then coked in the oven 27. The coked product may then be charged into the retort 21 which is preferably heated by the waste gases,

which have been used in heating the retort V 12 and is therefore maintained at a lower temperature than that'of the lower retort. Hydrochloric acid gas or chlorin or other chlorinating agent, is introduced through the conduit 25. Iron oxid present in tho aluminum ore is thus chlorinated and the resulting" iron chloride passesthrough the vapor line 26. Other impurities in the aluminumore which are more readily at-.-

tacked by chlorin than alumina are also removed from the aluminum ore in the retort The aluminum ore thus purified is conin it'is subjected'to the action of chlorin higher temperature than that obtaining in the preliminary retort. maintained is sufficient to cause the. reaction between alumina and chlorin resulting in the production of aluminum chlorlde va-' pors which are removed through the vapor the aluminum ores.

1 line 13.

In a modified form of the invention thesimultaneously. Although the retort 21 may be omitted in case it is desired to use this form of the invention, this may also be accomplished bymaintaining the hopper '31 in an open position and closing the conduit 26 so that chlorin from the pipe 25 may pass into the oven 27 to accomplish chlorina- The temperature of chlorin or hydrochloric I tion of the reactive iron compounds. The coked product is removed from the oven 27 before any substantial portion of alumi na is attacked and is discharged directly into the main retort 12 inwhich formation of aluminum chloride occurs.

- While I have described a specific form of apparatus and described the details of the process which I now consider most desirable I intend that only such limitations be imposed as indicated in the appended claims.

- \Vhat I claim is:

1. In combination with a' main retort 'adapted for the continuous treatment of materials for the production of aluminum chloride, an oven in which an alumina-carbon mixture may be coked, means for admitting a chlorinating agent into said oven, and means for continuously transferring the heated coked product from the oven into the main retort.

2. In combination with a main retort adapted for the continuous treatmentof materials for the production of aluminum chloride. an oven in which an alumina-carbon'mixture maybe coked, means for continuously transporting the mixture through the oven, means-for admitting a chlorinating agent'into the oven and means for continuously transferring the heated coked product into the main retort.

3. The process of -making aluminum chloride which consists. in simultaneously coking and purifying a mixture of aluminum ore and carbonaceous material by heat- 7 mg and chlorinating at a relatively low temperature, and then without loss of heat chlorinatingthe purified coked mixture at a relatively high temperature.

ride which consists in simultaneously coking l. The process of making aluminum chlo and purifyinga mixture of aluminum ore and carbonaceous material by heating and chlorinating under conditions such that no substantial chlorination of aluminum occurs, and then without loss of heat chlorinating the purified coked mixture under such conditions as to produce aluminum cl. oride.

5. The process of making aluminum chloride which consists in continuously and simultaneously coking and purifying a mixture of aluminum oreand carbonaceous material by heating and chlorinating in an oven provided therefor, under conditions such that no substantial chlorination of aluminum occurs, continuously transferring the hot purified mixture from the oven to a retort, chlorinating the purified coke mixture inthe retort under such conditions as to produce aluminum chloride, and continuously withdrawing the reaction products. 

